European Journal of Vascular & Endovascular Surgery
Volume 39, Issue 2 , Pages 153-154, February 2010

Carotid Denervation by Adventitial Stripping: A Promising Treatment of Carotid Sinus Syndrome?

  • P. Kolh

      Affiliations

    • Corresponding Author InformationTel.: +32 4 366 7163; fax: +32 4 366 7164.

University of Liege Hospital (CHU ULg), Cardiovascular Surgery Department, B35 Sart Tilman, 4000 Liege, Belgium

Received 2 October 2009; accepted 3 October 2009. published online 07 December 2009.

Article Outline

 

The baroreflex is an important component of the physiological short-term control of the blood pressure. Baroreceptors are mainly located in the wall of the aortic arch and of the internal carotid artery (ICA). The carotid sinus nerve (CSN)a contains afferent fibres travelling from the carotid sinus' baroreceptors located in the adventitia of the ICA. It joins the glossopharyngeal (IX) nerve and ends in the nucleus tractus solitarius in the brain stem. The efferent loop is conducted by the vagus (X) nerve to the heart leading to a physiologic bradycardia and inhibited atrio-ventricular conduction, in response to systemic hypertension. Also, a blocked sympathetic nerve system causes venodilatation, decreasing ventricular preload, and vasodilatation, both leading to decreased blood pressure.

Carotid sinus syndrome (CSS) is caused by a pathologic overshoot of this baroreflex and is characterised by exaggerated bradycardia and hypotension in response to carotid sinus stimulation, in situations such as shaving, wearing tight collar or head turning. The triggering events might vary considerably overtime in any individual patient, but the syndrome can be reproduced by carotid sinus massage.2 CSS prevalence could be as high as 45% in elderly patients.3 If left untreated, CSS mortality rates could exceed 25% within 5 years.4

The clinical manifestation of the syndrome is typically of recurrent syncope, but also of dizziness and falls. It is predominantly either cardioinhibitory (severe bradycardia or asystole) or vasodepressor (hypotension). The contribution of each of these two factors to systemic hypotension and cerebral hypoperfusion may differ considerably and should be assessed before embarking on specific treatments.

While current European Society of Cardiology and American College of Cardiology/American Heart Association guidelines2, 5 recommend dual-chamber pacing for repeated syncope in patients in whom the cardioinhibitory response is the attributable cause of symptoms, pacemaker implantation is not effective in vasodepressor CSS. Therefore, various surgical approaches aiming at interrupting the pathological baroreceptor reflex have been described. Among those, transection of the glossopharyngeal nerve requires a craniotomy and may cause loss of gag reflex and taste perception of the posterior third of the tongue. A simple transection of the carotid nerve is likely not sufficient, as separate connections to pharyngeal branches of the vagus nerve, vagus nerve itself, sympathetic trunk, and superior cervical ganglion were commonly observed in a recent anatomical study.1

In this issue of the Journal, Toorop et al.6 evaluated the efficacy of carotid denervation by adventitial stripping of the ICA in 27 patients with a history of repeated syncope and dizziness and in whom CCS was confirmed by carotid sinus massage. Within the 30-day follow up period, 25/27 patients became syncope free and 24/27 pacemaker free. Heart rate significantly increased one week postoperatively, however without clinical relevance, while blood pressure did not statistically change.

These early results are certainly encouraging, but the authors should report long-term follow of these patients before this original technique for the treatment of CSS could be further assessed and possibly recommended. Indeed, reinnervation of the baroreceptive regions has been demonstrated, at least in rats.7

In the meantime, as Toorop et al.1 correctly pointed out, their anatomical study supported the contention that dissection during carotid endarterectomy should be limited to the circumference of the intended clamping place of the distal ICA, thereby avoiding damage of the CSN or carotid sinus afferents near the carotid bifurcation and peri- or postoperative changes in blood pressure or heart rate in endarterectomised patients.

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References 

  1. Toorop RJ, Scheltinga MR, Moll FL, Bleys RL. Anatomy of the carotid sinus nerve and surgical implications in carotid sinus syndrome. J Vasc Surg. 2009;50:177–182
  2. Moya A, Sutton A, Ammirati F, Blanc JJ, Brignole M, Dahm JB, et al. Guidelines for the diagnosis and management of syncope (version 2009). Eur Heart J. 2009;30:2631–2671
  3. Kenny RA, Richardson DA, Steen N, Bexton RS, Shaw FE, Bond J. Carotid sinus syndrome: a modifiable risk factor for nonaccidental falls in older adults (SAFE PACE). J Am Coll Cardiol. 2001;38:1491–1496
  4. Maloney JD, Jaeger FJ, Rizo-Patron C, Zhu DW. The role of pacing for the management of neurally mediated syncope: carotid sinus syndrome and vasovagal syncope. Am Heart J. 1994;127:1030–1037
  5. Gregoratos G, Abrams J, Epstein AE, Freedman RA, Hayes DL, Hlatky MA, et al. ACC/AHA/NASPE 2002 Guideline update for implantation of cardiac pacemakers and antiarrhythmia devices–summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE Committee to Update the 1998 Pacemaker Guidelines). J Am Coll Cardiol. 2002;40:1703–1719
  6. Toorop RJ, Scheltinga MR, Huige MC, Moll FL. Clinical results of carotid denervation by adventitial stripping in carotid sinus syndrome. Eur J Vasc Endovasc Surg. 2010;39:146–152
  7. Cai GJ, Li L, Xie HH, Xu JJ, Miao CY, Su DF. Morphological evidence of reinnervation of the baroreceptive regions in sinoaortic-denervated rats. Clin Exp Pharmacol Physiol. 2003;30:925–929
  • a Various other names for the CSN include nerve of Hering, ramus descensus glossopharyngei, ramus caroticus glossopharyngei, intercarotid nerve or Castro nerve.1

PII: S1078-5884(09)00568-1

doi:10.1016/j.ejvs.2009.11.001

Refers to article:

  • Clinical Results of Carotid Denervation by Adventitial Stripping in Carotid Sinus Syndrome , 14 October 2009

    R.J. Toorop, M.R. Scheltinga, M.C. Huige, F.L. Moll
    European Journal of Vascular & Endovascular Surgery February 2010 (Vol. 39, Issue 2, Pages 146-152)

European Journal of Vascular & Endovascular Surgery
Volume 39, Issue 2 , Pages 153-154, February 2010

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